Conventional cellular telecommunications networks include mobile switching centers (MSCs) each operating to route calls between base stations that include radio equipment for serving one or more cells in the cellular network and other MSCs or public switched telephone networks (PSTNs). Conventional MSCs handle both bearer traffic for transporting user information (e.g., voice or other data in an integrated service, digital network (ISDN)) and signaling traffic for establishing and controlling call connections and managing the cellular network. The MSC exchanges signaling information with other MSCs and with other networks (e.g., PSTNs) for purposes of call set up, handovers, and coordinating call routing. In addition, the MSC directs the operations of base stations that support radio communications with mobile devices in individual cells of the cellular network.
Distributed MSCs (e.g., as can be used with 3GPP, Release 4) perform the same general functions as a conventional MSC but include an MSC server for handling signaling traffic and multiple media gateways for handling bearer traffic. The MSC server includes the intelligence and complexity of the distributed MSC, and the media gateways are controlled by the MSC server. The media gateways can be geographically distributed, can connect to multiple base stations, and serve to route bearer traffic under control of the MSC server.